The present inventions relates to a flavor composition and more particularly to a flavor encapsulated in a glassy carbohydrate matrix composed of a composition comprising a blend of polydextrose and lactitol.
There is a long history of patents being issued for flavor encapsulation via extrusion of carbohydrate glasses, e.g., U.S. Pat. Nos. 5,009,900, 5,087,461, 5,603,971, 4,232,047, 4,820,534, and 4,689,235 and International Patent Applications WO 94/23593, WO 96/38055, WO 98/20756, and WO 86/00502. All these patents and patent applications disclose the requirement of adding water or other plasticizer during the extrusion process, and this inhibits the glassy property of the matrix. For this reason, improvements in such materials are needed.
We have found that a composition comprising a blend of polydextrose and lactitol eliminates the need for the addition of water or other plasticizers) in the extrusion. This blend improves the encapsulation properties of the technique, since the presence of other than small amounts of water, for instance above about 3 to 3.5% by weight, in the final product will inhibit the glassy properties of the carbohydrate matrix. It also eliminates the need for any plasticizer removal techniques mentioned in, for example, U.S. Pat. No. 5,603,971. Furthermore, the shelf life of the flavor is also extended because it will ensure that the glass transition temperature is above room temperature ( i.e., representative of shelf life conditions) during storage.
Accordingly, the present invention relates to a flavor composition in the form of a homogeneous emulsion comprising a flavor encapsulated in a glassy carbohydrate matrix composed of a composition comprising a blend of polydextrose and lactitol.
The amount of flavor in the composition may be up to about 30%, preferably is from about 0.1 to 25%, and more usually from about 0.5 to 20% by weight based on the weight of the composition.
The invention is particularly advantageous for savory flavors with examples of such flavors being tomato, chicken, beef and other grilled flavors.
The matrix provides an effective barrier against both diffusion and oxidation because of its low permeation properties in the glassy state. The matrix composition is preferably adjusted to ensure it retains its glass behavior in typical storage conditions.
The matrix material may contain small quantities of an emulsifier, e.g. from about 0.1 to 5% and preferably from about 0.5 to 3.5% by weight of the matrix. The purpose of the emulsifier is to create a homogeneous product at the extruder outlet so that the flavor receives maximum protection from the matrix.
The amount of lactitol in the blend of polydextrose and lactitol may be from about 5 to 50%, preferably from 10 to 40%, and more preferably from 15 to 35% by weight based on the weight of the blend.
The flavor composition in the form of a homogeneous emulsion comprising a flavor encapsulated in a glassy carbohydrate matrix may be prepared by feeding a blend of polydextrose, lactitol and, preferably, small quantities of an emulsifier into an extruder, mixing, and heating up to from about 90xc2x0 C. to 130xc2x0 C., preferably from 100xc2x0 C. to 125xc2x0 C., adding the flavor to this blend, and transporting the entire mixture with mixing along the extruder barrel to the exit where the homogeneous emulsion exits via a die on the extruder outlet, is cooled to room temperature via ambient air, and is ground into a powder, e.g. through a 4 mm mesh screen.
Any emulsifier with a hydrophilic/lipophilic balance (HLB) in the range of about 3 to 10 may be used, preferably an emulsifier with a HLB Value in the range of 6 to 9. The emulsifier may be, for instance, Panodan(copyright) 150K (Danisco), a blend of diacetyl tartaric acid ester with mono-diglyceride with a HLB value between 7 and 8 which works effectively in the system. Other esters having the recited HLB values may be used.
While the technology of extrusion to improve flavor shelf life has been described in numerous patents and literature, this is the first known use of the polydextrose/lactitol blend combination as the carbohydrate matrix. In order to provide adequate flavor protection, this matrix material must have the following characteristics:
1) A glass transition temperature high enough to ensure the system remains in the glassy state throughout storage conditions. A matrix material in the glassy state will have very low diffusion values, thus preventing loss of the flavor component. This must be accomplished not only for the flavor system, but also for any applications in which it would be stored.
2) The ability to form a homogeneous emulsion between the flavor and matrix components. This may be facilitated by the addition of a small amount of emulsifier.
Polydextrose has a relatively high glass transition temperature, but is a hydroscopic material (Aw value of 0.07 at 20.6xc2x0 C.). The glass transition temperature drops as moisture is added, so that the use of polydextrose in a flavor system with higher moisture content would be expected to result in unacceptable glass transition behavior.
We have found to the contrary that, in order to obtain a high glass transition temperature without the full hydroscopic behavior exhibited by pure polydextrose, the amount of water in the blend of polydextrose and lactitol is preferably less than 3.5% by weight, and more preferably less than 3% by weight based on the weight of the blend, to achieve a glass transition temperature that is above 40xc2x0 C. Especially preferred water contents are less than 2.5% by weight based on the weight of the blend. The desired amount of water is conveniently achieved by not adding water for extrusion.